Breast cancer is the most common cancer and the second leading cause of cancer death among American women of all races. Despite improvement of recurrence and survival rates of breast cancer in the United States, significant differences between white and black women remain. Previous studies have found that more advanced and aggressive tumors and less than optimal treatment may explain the higher recurrence and lower survival rates for black women as compared to white women. However, to the best of our knowledge, there has been no research that jointly considers potential factors that include not only individual level information such as treatment history and tumor characteristics, but also provider characteristics, and physical and social environmental information. Due to limitations of current analytic methods and the lack of comprehensive data sets, researchers have not been able to differentiate the relative effect each factor contributes to the overall racial disparities at different levels (census tract or individual levels). We will use the CDC-funded special studies, including Patterns of Care study, Enhancing Cancer Registry Data for Comparative Effectiveness Research (CER), and the Patient Centered Outcomes Research (PCOR), to examine the determinants of racial disparities in breast cancer survival and recurrence using a novel multilevel mediation analysis. The PoC, CER, and PCOR studies collected complete standard of care and tumor characteristic information for female breast cancer patients. The Louisiana Tumor Registry participated in all these studies and collected the required information from Louisiana breast cancer patients. We plan to link the datasets with census data and many other data sources to obtain environmental and provider information. We propose a novel statistical method that can jointly consider potentially correlated multiple mediators, and differentiate the indirect effect from every individual factor from different levels that may contribute to the race-breast cancer survival and recurrence relationship. If successful, this proposal will provide the most comprehensive exploration of racial disparities in breast cancer patients? recurrence and survival in the United States.